patch 8.2.1411: when splitting a window localdir is copied but prevdir is not

Problem:    when splitting a window localdir is copied but prevdir is not.
Solution:   Also copy prevdir. (closes #6667)

Author: brammool

src/clientserver.c

@@ -596,7 +596,8 @@ build_drop_cmd(
     ga_concat(&ga, cdp);
 
     // Call inputsave() so that a prompt for an encryption key works.
-    ga_concat(&ga, (char_u *)"<CR>:if exists('*inputsave')|call inputsave()|endif|");
+    ga_concat(&ga, (char_u *)
+		       "<CR>:if exists('*inputsave')|call inputsave()|endif|");
     if (tabs)
 	ga_concat(&ga, (char_u *)"tab ");
     ga_concat(&ga, (char_u *)"drop");
@@ -621,7 +622,8 @@ build_drop_cmd(
 	ga_concat(&ga, p);
 	vim_free(p);
     }
-    ga_concat(&ga, (char_u *)"|if exists('*inputrestore')|call inputrestore()|endif<CR>");
+    ga_concat(&ga, (char_u *)
+		  "|if exists('*inputrestore')|call inputrestore()|endif<CR>");
 
     // The :drop commands goes to Insert mode when 'insertmode' is set, use
     // CTRL-\ CTRL-N again.

src/testdir/test_cd.vim

@@ -168,6 +168,15 @@ func Test_prev_dir()
   call delete('Xdir', 'rf')
 endfunc
 
+func Test_lcd_split()
+  let curdir = getcwd()
+  lcd ..
+  split
+  lcd -
+  call assert_equal(curdir, getcwd())
+  quit!
+endfunc
+
 func Test_cd_completion()
   call mkdir('XComplDir1', 'p')
   call mkdir('XComplDir2', 'p')

src/version.c

@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1411,
 /**/
     1410,
 /**/

src/window.c

@@ -1385,6 +1385,8 @@ win_init(win_T *newp, win_T *oldp, int flags UNUSED)
 #endif
     newp->w_localdir = (oldp->w_localdir == NULL)
 				    ? NULL : vim_strsave(oldp->w_localdir);
+    newp->w_prevdir = (oldp->w_prevdir == NULL)
+				    ? NULL : vim_strsave(oldp->w_prevdir);
 
     // copy tagstack and folds
     for (i = 0; i < oldp->w_tagstacklen; i++)